Use of tuf PCR for staphylococcal and streptococcal genus detection in endophthalmitis

Abstract

AbstractPurpose This study reports the contribution of specific conventional PCR of the Staphylococcus and Streptococcus genera followed by sequencing for the microbiological diagnosis of endophthalmitis.Methods Specific PCR assays targeting the tuf gene of the Staphylococcus and Streptococcus genera were performed in addition to the reference techniques (conventional culture and panbacterial PCR) on samples of aqueous humor and/or vitreous in patients with acute post operative endophthalmitis when Staphylococcus or Streptococcus had been identified using reference methods or no identification had been possible.Results Out of the 125 samples analyzed (60 aqueous humor and 65 vitreous of 85 patients) , the culture was positive in 61 cases (48.8%) and panbacterial PCR was positive in 78 cases (62.4%). By combining culture and panbacterial PCR bacterial identification was obtained in 94 of the 125 samples (75.2%, 72 Staphylococcus, 22 Streptococcus). Staphylococcus‐specific PCR was positive in 72 out of the 103 samples tested and allowed 8 additionnal identifications. The Streptococcus‐specific PCR was positive in 13 cases. The Streptococcus‐specific PCR provided no additional diagnosis to the pan‐bacterial PCR. By adding Staphylococcus and Streptococcus tuf specific PCR to the reference methods, bacterial identification was obtained in 102 of the 125 samples (81.6%, 80 Staphylococcus, 22 Streptococcus).Conclusion The Staphylococcus‐ and Streptococcus‐specific techniques used in this study were complementary to the panbacterial PCR techniques and improved sensitivity in the identification of Staphylococcus and better identification of the species with sequencing.